Plastic Injection Molding

Plastic Injection Molding: Applications & Benefits

Although plastic injection molding was first invented in 1872, it didn’t surpass steel production until the 1970s. Its rise in popularity is due to manufacturers realizing that it allowed them to cost-effectively develop durable, complex parts. 

In today’s world, just about every manufacturer is taking advantage of plastic injection molding. And, with the evolution of technology, both the design and manufacturing process of molds is easier and more precise than ever before. 

In this article, we’ll discuss the overall process of plastic injection molding, as well as its many industry applications and benefits.

What Is Plastic Injection Molding?

Plastic injection mold process

Plastic injection molding is an efficient way to mass-produce plastic parts. In layman’s terms, the process itself involves injecting liquefied plastic into a mold (which is usually made from hardened or pre-hardened aluminum or steel).

To go into more detail, the injection molding process starts by gravity-feeding polycarbonate resin (thermoplastic polymers) from a hopper into a heated conveyor where a long, motor-controlled screw repeatedly grinds and rotates the resin. Eventually, the heating of the plastic and the rotation of the screw creates sufficient pressure and heat to break down the resin into molten plastic.

That molten plastic is then fed into a mold where the plastic forms into the mold’s inner cavities. The mold is then instantly cooled through multiple channels that carry a mixture of antifreeze fluid (typically ethylene glycol) and water. Once the part has cooled, the mold opens, and the substrate or molded part is ejected.

Industry Applications

You would be hard-pressed to find an industry that doesn’t need or use injection molding. Aside from the obvious applications like manufacturing plastic bottles, containers, and bulk packaging, there are other applications where the profiles and dimensional tolerances of the finished part are critical. Let’s take a look at some of them:

  • Automotive Industry: Auto manufacturers use high-volume injection molding to create a dashboards, bumpers, and other interior and exterior components
  • Healthcare & Pharmaceutical Industries: Companies in this industry have to purchase multiple plastic products in bulk. They see these single-use plastic products as essential to maintaining sterility and protecting users against germs.
  • Aerospace: The aerospace industry sees molded plastic as a critical component of reducing the overall weight of a plane. 
  • Agriculture: Other industries like agriculture have followed aerospace’s lead and now see plastic components as critical to helping reduce the weight of equipment and machinery. 
  • Electronics: The frames of mobile phones, laptops, computers, and tablets are all molded.

We could go on—but you get the idea. The versatility and precision of plastic injection molding is what makes it so necessary for most industries.


As previously mentioned, injection molding is an extremely versatile process. It’s great for large volume applications, and can also help shorten a company’s product-to-market timeline. 

It also dramatically reduces the costs and time required to make prototypes, which helps companies make faster and more informed decisions. Engineers can quickly get a prototype from a company offering injection molding services. They can then test the fit, form, and function of the part before moving forward with large-scale production. Since so many prototypes are needed before production, relying on plastic molding services is essential. 

Other benefits include lowering the weight of a given integrated assembly, including a large frame (airplane) or equipment and machinery (agriculture). Plastic molded parts also provide excellent impact resistance and can handle the harshest weather conditions without the risk of corrosion or material degradation.

H2: Learn More About Plastic Injection Molding TodayDo you have questions about injection molding? Contact Silver Basis Engineering. Serving clients around the world, we are an award-winning, client-centric plastic injection molding manufacturer capable of producing highly complex parts and assemblies, while also functioning as a critical design partner to OEMs in the automotive industry.